The present invention relates to mobile staging and scaffolding for working in high places. More particularly, the invention relates to mobile scaffolds intended for use in environments requiring that the user depart from the scaffold structure to work in the surrounding vicinity of the scaffold.
Various mobile scaffold constructions have been devised for working in high places. These devices typically include a frame and a plurality of wheels for enabling the structure to be propelled over distances. Attached to the frame are typically stairs or ladder rungs enabling a user to climb the structure. Typically, on each side of the stairs or ladder rungs are handrails for safety purposes.
The mobile scaffolding often includes a platform at the top of the stairway enabling a user additional area to operate. For example, U.S. Pat. No. 2,362,170 and U.S. Pat. No. DES.411,019 describe mobile scaffold structures including a plurality of stairs which are framed on each side with handrails. At the top of the stairway, a platform is provided which also includes railing on both the left and the right side of the platform. However, some mobile scaffolding, such as described in U.S. Pat. No. 2,363,170, include a platform which is open-ended so that after climbing the scaffold stairway and reaching the platform, one can extend from or walk off the platform""s end. The open-ended platform provides the user with freedom to operate beyond the constrains of the platforms itself and a departure point enabling the user to depart from the scaffolding to work in other areas, such as upon the wings or fuselage of an airplane. Unfortunately, users of scaffolding including open-ended platforms are susceptible to falls making such scaffold unacceptably dangerous. In fact, such scaffolding has been prohibited throughout much of the United States pursuant to municipal, state and Federal safety codes.
Alternative, mobile scaffolds typically include a platform at the top of the stairway which is surrounded on three sides by safety railing. Although this construction is significantly safer than mobile scaffolds having a platform with railing on only two sides, the construction hinders a user""s ability to operate or manipulate tools beyond the physical constrains of the railing itself.
Thus, there is a significant need for a mobile scaffold which enables users to safely work in high places outside of the dimensions of the scaffold itself. Even more particularly, there is a need for a mobile scaffold which enables users to operate safely on the exterior of airplanes, such as on the wings and fuselage, while being protected against falls.
Further, it would be advantageous to provide a mobile scaffolding which enables users to safely work outside of the physical constrains of the scaffolding which is adjustable in height.
The present xe2x80x9cAerial Life Saverxe2x80x9d invention addresses the aforementioned disadvantages by providing a new solution for a safe working environment. Applications for the aerial lifesaver of the present invention are unlimited, extending to any work place environment where human lives should be protected against falls. The aerial lifesaver may be used in connection with any tasks which are required to be conducted on top of any vehicle, such as upon airplanes, trains, trucks, automobiles, etc. In addition, the aerial lifesaver may be used in connection with work on stationary structures, such as buildings, water tanks, bridges, or wherever people are susceptible to the danger of falls, including workers engaged in tasks involving service, maintenance and construction.
For manufacturing simplicity, it is preferred that the aerial lifesaver""s base section is rectangular including a pair of longitudinal beams and a pair of transverse beams which are joined at their ends to form a frame. Attached to each corner of the frame are wheels enabling the base section to be easily moved. The base section also includes a turret assembly for pivotally-mounting the step assembly so that the step assembly can be lowered or raised according to the needs of the user. The step assembly further includes a plurality of stairs or ladder rungs enabling the step assembly to be climbed. In order to raise and lower the step assembly, any suitable means may be utilized. Preferably, the step assembly is raised or lowered with a hydraulic or pneumatic system. The step assembly preferably also includes handrails on each side extending along its length for protecting the user.
The aerial lifesaver also includes a platform at the top of the step assembly. The platform may be of any size or configuration, depending on the tasks needing to be completed. Preferably, the platform includes side handrails on each side and an operable front gate. Opening of the front gate provides for an open ended construction enabling a user to climb the stairway, cross the platform, and walk off its end.
Protecting the user from falling is a safety assembly including a safety rail which projects horizontally overhead of the platform. The safety rail is maintained in place by a safety rail support arm, which in a preferred embodiment extends from the uppermost extremity of the step assembly. The safety rail may take any number of constructions as can be determined by those skilled in the art. For example, the safety rail may be constructed of a simple I-beam. Preferably, the safety rail also includes one or more anchor points for attaching a lifeline.
The aerial lifesaver of the invention is intended for use in cooperation with persons wearing a harness attached to a lifeline. Preferably, the safety lifeline is extendible and self-retracting including an inertial lock similar to those found in conventional automobile seat belt assemblies so that if one using the aerial lifesaver falls from the platform, the inertial lock will prevent further extension of the lifeline and further falling of the user.
In operation, before the aerial lifesaver is moved to a desired work location, a required number of lifelines of required lengths are attached to the platform siderails and anchor points. After the step assembly is lifted to a desired height, the user wearing the proper harness climbs the stairway protected by the stairway siderails. Thereafter, he walks upon the platform protected on three sides by the side rails and closed gate. Before opening the gate, the user attaches the free end of his harness to the platform end of the lifeline extending from an anchor point. Upon opening the gate, the platform becomes open-ended and the user is free to leave the platform and walk safely to a working position. The user is protected from falls, and particularly protected against falling off the platform""s open end, as the lifeline connected to the user""s harness prevents the user from striking the ground.
Thus, an object of the present invention is to provide an aerial lifesaver which enables users to work in high places, such as on the fuselage or wing of an airplane.
It is another object of the present invention to provide an aerial lifesaver which enables one to exit the structure but still be protected against inadvertent falls.
Other features and advantages of the present invention will be appreciated by those skilled in the art upon reading the detailed description which follows with reference to the attached drawings.